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#include <map>
#include "cola.h"
using namespace std;
namespace cola {
namespace ccomponents {
struct Node {
unsigned id;
bool visited;
vector<Node*> neighbours;
Rectangle* r;
};
// Depth first search traversal of graph to find connected component
void dfs(Node* v,
set<Node*>& remaining,
Component* component,
map<unsigned,pair<Component*,unsigned> > &cmap) {
v->visited=true;
remaining.erase(v);
cmap[v->id]=make_pair(component,component->node_ids.size());
component->node_ids.push_back(v->id);
component->rects.push_back(v->r);
for(unsigned i=0;i<v->neighbours.size();i++) {
Node* u=v->neighbours[i];
if(!u->visited) {
dfs(u,remaining,component,cmap);
}
}
}
}
using namespace ccomponents;
// for a graph of n nodes, return connected components
void connectedComponents(
vector<Rectangle*> &rs,
vector<Edge> &es,
vector<Component*> &components) {
unsigned n=rs.size();
vector<Node> vs(n);
set<Node*> remaining;
for(unsigned i=0;i<n;i++) {
vs[i].id=i;
vs[i].visited=false;
vs[i].r=rs[i];
remaining.insert(&vs[i]);
}
for(vector<Edge>::iterator e=es.begin();e!=es.end();e++) {
vs[e->first].neighbours.push_back(&vs[e->second]);
vs[e->second].neighbours.push_back(&vs[e->first]);
}
map<unsigned,pair<Component*,unsigned> > cmap;
while(!remaining.empty()) {
Component* component=new Component;
Node* v=*remaining.begin();
dfs(v,remaining,component,cmap);
components.push_back(component);
}
for(vector<Edge>::iterator e=es.begin();e!=es.end();e++) {
pair<Component*,unsigned> u=cmap[e->first],
v=cmap[e->second];
assert(u.first==v.first);
u.first->edges.push_back(make_pair(u.second,v.second));
}
}
}
// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=4:softtabstop=4
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